The free online tuner for every instrument

Online Tuner listens through your microphone and shows the note you play, its frequency and how many cents you are flat or sharp. Tune a guitar, ukulele, violin, bass or any instrument with the chromatic tuner — free, with no app and no sign-up.

Start tuner Choose your instrument

Press Start and allow the microphone

Your browser will ask to use the microphone. Choose Allow.

A4440Hz

Tap a string to hear it and tune only that string. Audio is analysed on this device and never uploaded. All 14 instruments →

What it does: Hears the note you play and shows its name, octave, Hz and cents; string-by-string modes for guitar, bass, ukulele and violin
What it does not do: Record or upload audio · detect chords
Reference pitch: A4 = 440 Hz, adjustable 415–466 Hz
Tested with: 58 studio recordings of 11 instruments (right note on about 95% of frames at normal volume) and test tones from B0 to C6
Made by: The Appcellent team
Updated: November 2026

Tuner not hearing you?

Allow the microphone. If you blocked it: in Chrome or Edge, click the icon left of the address bar → Microphone → Allow, then reload. In Safari on iPhone, tap aA → Website Settings → Microphone → Allow. In Firefox, click the crossed-out microphone in the address bar. On a Mac, also check System Settings → Privacy & Security → Microphone for your browser.
Open the page in Safari or Chrome. In-app browsers (Instagram, Facebook, TikTok) often block the microphone.
Play one note at a time, louder. Hold your phone or laptop close to the instrument and let the string ring. A quiet room helps.
Wrong octave or jumping notes? Let the attack fade for a moment — the reading settles once the note is steady.
No microphone at all? Tap a string button to hear its note and tune by ear.

Tuners for every instrument

Each tuner knows the strings or tuning notes of its instrument, so you see exactly which string to turn and which way.

Guitar→ E A D G B E Ukulele→ G C E A Violin→ G D A E Bass→ E A D G Banjo→ G D G B D Cello→ C G D A Viola→ C G D A Mandolin→ G D A E Flute→ Concert pitch Clarinet→ B♭ instrument Trumpet→ B♭ instrument Saxophone→ Alto sax (E♭) Trombone→ Concert pitch French horn→ Horn in F Voice & pitch→Pitch detector Vocal range→Find your voice type

Alternate guitar tunings

Drop D, open D, open G, DADGAD and more — each page has the notes, frequencies and a tuner already set to that tuning.

Open D→D A D F♯ A D Drop D→D A D G B E Drop C→C G C F A D Drop B→B F♯ B E G♯ C♯Open G→D G D G B D C Standard→C F B♭ E♭ G C Open E→E B E G♯ B E Drop A→A E A D F♯ B C♯ Standard→C♯ F♯ B E G♯ C♯B Standard→B E A D F♯ B Half Step Down→E♭ A♭ D♭ G♭ B♭ E♭12-String Guitar→E A D G B E (pairs)Open C→C G C G C E 7-String Guitar→B E A D G B E DADGAD→D A D G A D Open A→E A E A C♯ E

Built to be simple, precise and private

No downloads and no account. Open the page, allow the microphone and tune.

Private by design

Sound is analysed in your browser. Nothing is recorded or uploaded, so there is nothing to store.

Shows every cent

The needle shows cents — hundredths of a semitone — and turns green within 5 cents of the note.

Works on any device

Phone, tablet or laptop: any modern browser with a microphone, including Safari and Chrome.

Questions

How does an online tuner work?

It listens through your microphone, finds the pitch of the note you play many times per second and compares it with the nearest note. The needle shows how many cents (hundredths of a semitone) you are flat or sharp.

Is this online tuner free?

Yes. It is free, has no ads, needs no account and does not ask you to install anything.

Is my audio recorded or uploaded?

No. The sound is analysed in your browser on your own device and is never recorded, stored or sent anywhere.

What is a chromatic tuner?

A chromatic tuner recognises all 12 notes of the scale, so it works for any instrument and any tuning. Instrument modes (guitar, bass, ukulele, violin) add string-by-string targets.

Why does the tuner not react?

Allow microphone access when your browser asks. If you blocked it before, open your browser’s site settings and allow the microphone for onlinetuner.app. Play a little louder and closer to the device in a quiet room.

Can I change the reference pitch (A = 440 Hz)?

Yes. Use the A4 control under the tuner to set any reference from 415 to 466 Hz, for example A = 442 Hz for some orchestras or A = 432 Hz.